The measures target Jamaat Nusrat al-Islam wal-Muslimin (JNIM) -- designated a terrorist organization by Washington last September -- and its commander Bah Ag Moussa, an army deserter who led a raid on a Malian military base that killed 21 former comrades.

"Treasury is targeting the leadership of JNIM, Al-Qaeda's branch in Mali, for its destabilizing role conducting terrorist attacks across the country," said Treasury Under Secretary Sigal Mandelker.

"As a leader within JNIM, Bah Ag Moussa directly contributes to the violence and instability fueled by Al-Qaeda's terrorism," he said.

The sanctions freeze all US assets owned by the group or its leaders, and block US citizens and institutions from having financial dealings with them.

Despite aid from French and UN forces, Mali struggles to quell unrest that began in 2012 in the north and spread to other parts of the country in Africa's Sahel region.

French forces in January 2013 intervened in northern Mali after the region was overtaken by jihadist forces and a peace agreement was signed in 2015 with some armed factions, but parts of the country remain out of the control of the government and the armed forces.